Iowa Addresses Soybean Rust Concerns

An Iowa team is developing an action plan to prepare for and respond to a new soybean disease. Asian soybean rust has not been found in North America and experts don't expect it to hit the United States this growing season. The disease could cost the soybean industry more than $1 billion a year in fungicides if it shows up in the United States.

The group began meeting in the fall of 2003 to discuss how to handle reports of soybean rust. The team members represent Iowa State University, the Iowa Department of Agriculture and Land Stewardship, the Iowa Soybean Association/Iowa Soybean Promotion Board and the United States Department of Agriculture Animal and Plant Health Inspection Service.

Greg Tylka, a plant pathologist at Iowa State, says the team's goal is to keep farmers, crop consultants, extension specialists and researchers informed on how to spot the disease, where to take samples for accurate identification and how to minimize yield loss.

"We want to alleviate fears and let the public know there are well-trained people working on this potential problem. We have an effective and geographically widespread system to check for soybean rust," Tylka says.

Since Asian soybean rust is not present in the United States, few researchers have had the opportunity to study the disease. Iowa State has two researchers with expertise who are monitoring the movement of the fungus, developing weather-based models to predict when and where rust could occur and analyzing where the disease could overwinter.

"We are developing an effective system to diagnose and monitor for soybean rust," Tylka says.

The team plans to hold five training workshops for more than 2,000 crop consultants and advisers during the last week in June to help them identify Asian soybean rust. These crop professionals are likely to be the first to detect the disease if it hits Iowa fields.

"There are some common soybean diseases that occur in Iowa that can be confused with soybean rust, so accurate diagnosis by experts is necessary," Tylka says. "Producers shouldn't make drastic management decisions without knowing all the facts."

Soybean rust is of national interest and could have serious economic implications for the soybean industry, Tylka says. The first few infections in each state need to be accurately and conclusively identified by USDA scientists. Once soybean rust is confirmed, trained individuals throughout Iowa will be able to identify and verify the disease.

Earlier this year team members tested how quickly the first samples could be verified by the USDA. An ISU Extension field crop specialist initiated the test by taking a false sample to the Plant Disease Clinic at Iowa State. It took less than 30 hours for the sample to make its way from the field to the clinic and on to Beltsville, MD for official confirmation by the USDA.

"That's pretty quick turn around," Tylka says. "Our goal is to have the same turn-around time, if needed, during the growing season."

Iowa is one of nine states to apply for a Section 18 emergency use exemption from the Environmental Protection Agency to allow producers to apply certain fungicides if the rust hits Iowa. The fungicides can only be applied after the problem is verified.

The team's purpose is to develop a comprehensive system to detect and respond to a pathogen that travels quickly and protect a multi-billion dollar industry. In 2003, more than 2.4 billion bushels of soybean were produced in 31 states. Iowa had the greatest area of soybean harvested with 10.5 million acres and produced 337.6 million bushels. In 2003, the United States produced 39 percent of the world's soybean, followed by Brazil with 26 percent, Argentina with 18 percent and China with 8 percent.

Soybean rust is found on every continent in the world except North America. The fungus was first identified in Japan in 1902. It was discovered in Australia in 1934 and from there it traveled to Africa. Brazilian soybean producers first experienced the disease during the 2002-2003 growing season.